HOLLYWOOD -- Simon Cowell and Fox network executives announced Monday at the TV Tour that he would leave "American Idol" at the conclusion of its current season, scheduled to launch Tuesday (January 12).

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At the same time, Cowell announced he'll be bringing his UK hit "The X Factor" to the network in 2011. "Idol" will continue with a replacement judge or judges.

"We're not going to try and find a Simon clone," said Peter Rice, Fox entertainment chair. "He's one of a kind."

As for his new talent show, Cowell said, "The auditions are done in quite a different way than 'Idol.' There is no upper age limit on this show. You can literally be 100 years old."

Cowell added that another main difference is that "X Factor" judges mentor contestants to the competition's conclusion. The two shows will air in different seasons -- fall for "X Factor," spring as usual for "Idol."

Cowell also said that he believes "Idol" will continue to be a success without him.

"I want to leave 'Idol' this year bigger and better than it's ever been before," he said.